fix ImageMagick command in Windows

[aboutqx]

Add OS detect to choose right command.

It seems that paperclip use identify as exe in windows,

Command :: SET PATH=C:\file-5.03-bin\bin;%PATH% & identify -format '%wx%h,%[exif:orientation]' "C:/Users/AppData/Local/Temp/5415c7fe534a63366b48d388f204c32820161028-7156-f2nblm.jpg[0]" 2>NUL.,

while only magick identify command works in windows,and there in no identify.exe in windows in the latest version ImageMagic.
And only Paperclip.options[:command_path] is used, the Paperclip.options[:image_magick_path] seems ignored.

About imageMagick in windows can be found there.

[tute]

Thank you, @aboutqx! I like this change.

I know master is now failing in CI for Ruby 2.2, I'm taking care of that. That makes it hard to do what I'll ask, but do you know you can set up paperclip for Windows in Travis CI with a regression test for this? Otherwise, I can't make sure we can reliably maintain this code.

Also, do you think we can abstract out this change to a single place in the codebase, and then call that configuration instead of checking three times whether we are on windows or not?

Thanks so much!

[tute]

the Paperclip.options[:image_magick_path] seems ignored.

Is this a bug? If so, we should address it. Thanks!

[houndci-bot]

Use the new Ruby 1.9 hash syntax.
Put a comma after the last item of a multiline hash.

[houndci-bot]

Use the new Ruby 1.9 hash syntax.

[aboutqx]

Glad for your reply.I've make it configurable by adding it to options,but I'm not familiar with Travis CI.

I've made some google,it seems that Windows is not supported in Travis CI right now,and I have no ideas.
Do you have nay solution?I'm fine with it unmerged.
Btw,the Paperclip.options[:image_magick_path] is never used,not sure if it's needed.

[tute]

It seems that Windows is not supported in Travis CI right now

huh, we can't test it then. We could tag those tests with windows_platform or alike, ignored by CI, so that people on Windows platforms can run them. But I don't have available window boxes to run them myself and verify the tests and code indeed work.

The Paperclip.options[:image_magick_path] is never used,not sure if it's needed.

Right, thanks! Just dropped the option.

[aboutqx]

Maybe another way is make the option is_windows default false ,then we'll need no tests on windows,and add a tip about changing it in windows while referencing the doc of ImageMagick.

Right now the error information didn't cover it,just return not idetentified,which is not clear.

[mike-burns]

Merged as 0d93e0f. Thank you!